A repair structure and construction method for a sandwich panel of a box body

Abstract

The present invention discloses a repair structure of a compartment sandwich panel, the compartment sandwich panel comprises a core material and a first skin and a second skin respectively laid on both sides of the core material in the thickness direction, and the first skin is a metal skin, the repair structure comprises a repair hole opened on the compartment sandwich panel, the repair hole is formed by cutting the first skin toward the core material along the thickness direction of the compartment sandwich panel, the repair hole does not penetrate the second skin, a filling block is filled in the repair hole, a repair skin covers the repair hole, the material of the repair skin is the same as that of the first skin, and the repair skin is welded to the first skin; the filling block is cut from the same material as the core material. The present application also discloses a construction method of the repair structure. By using the present application, the repair process can be effectively simplified, the safety of the repair structure can be improved, and the waterproof performance can be improved.

Description

Technical Field

[0001] The invention relates to a repair structure of a box sandwich panel and a construction method. Background Art

[0002] The sandwich panel of the car body adopts a sandwich structure, which is generally composed of a metal skin with a thickness of 0.6 to 1.5 mm, a frame, a core material, an adhesive, etc. During manufacturing and actual use, the car body sandwich panel is damaged due to dents, breakages, misaligned holes caused by operational errors or external forces, and the need to re-drill holes or add buried iron to install new equipment. The damaged parts need to be repaired to restore the integrity of the car body sandwich panel and ensure its normal use.

[0003] At present, the following steps are used to repair the damaged area: (1) Protect the area around the sandwich panel of the car body that needs to be repaired, cut off the skin of the repair area according to the square hole, and remove the damaged foam to form a hole, and then stuff the hole with foam tape of the same size to fill it up so that the foam surface of the repair surface is flat; (2) Cut metal strips on site according to the size of the hole and stuff them around the hole; (3) Fix the metal strips to the skin with rivets; (4) Press the repaired skin tape glue onto the opening, fix it with rivets, seal it with glue, and repaint it.

[0004] The above repair method can repair the damage, but it still has the following defects:

[0005] (1) Complicated process: It requires processes such as inserting metal strips, inserting metal strips, drilling holes, and riveting, which makes the repair work inefficient and time-consuming.

[0006] (2) Hidden dangers: After long-term use, the rivet heads are likely to protrude from the surface of the sandwich panel, causing "fish-eye" problems, affecting the appearance and performance; the sealant expands and contracts due to heat and cold, and is prone to cracking; long-term use and vibration are prone to cracking;

[0007] (3) Poor waterproof performance: There are many rivets around the skin, which are easy to loosen over time and may cause water leakage. Summary of the invention

[0008] In order to at least partially solve the above problems, the present invention first proposes a repair structure for a sandwich panel of a compartment, which can effectively simplify the repair process, improve the safety of the repair structure, and improve the waterproof performance. The specific technical solution is:

[0009] A repair structure for a compartment sandwich panel, the compartment sandwich panel comprises a core material and a first skin and a second skin respectively laid on both sides of the core material in the thickness direction, and the first skin is a metal skin, the repair structure comprises a repair hole opened on the compartment sandwich panel, the repair hole is formed by cutting the first skin toward the core material along the thickness direction of the compartment sandwich panel, the repair hole does not penetrate the second skin, a filling block is filled in the repair hole, a repair skin covers the repair hole, and the repair skin covers the repair hole, the material of the repair skin is the same as that of the first skin, and the repair skin is welded to the first skin; the filling block is cut from the same material as the core material. The repair hole is formed by the cut first skin and the core material. Preferably, the thickness of the repair skin is 0.6-0.8mm.

[0010] In this repair structure, the conventional method of fixing metal strips with rivets is eliminated, and the repaired skin is fixed to the sandwich panel of the car body by laser welding. The heat release of laser welding is small, and the metal deformation at the weld is small, so that the repaired skin can be basically flat and will not crack, ensuring the sealing of the repaired part. Since rivets are no longer used, the phenomenon of rivet heads protruding from the sandwich panel of the car body due to thermal expansion and contraction is avoided, ensuring the beauty of the repaired part.

[0011] The repair structure can be used for repairing a first skin made of metal material, for example, repairing a skin of a sandwich panel of a cabin in which the first skin is made of aluminum plate, carbon steel plate or stainless steel plate.

[0012] Furthermore, in order to ensure that the filling block can be stably connected to the sandwich panel of the compartment, the outer peripheral surface of the filling block is fitted with the inner peripheral surface of the repair hole and are bonded together with an adhesive.

[0013] Furthermore, the filling block has an outer side surface facing away from the second skin, and the outer side surface is 0.2-0.3 mm lower than the outer surface of the first skin. This design can avoid the appearance of bulge in the repaired skin due to the support of the filling block, which not only affects the appearance of the repaired area, but also generates internal stress in the repaired skin under long-term support, affecting the safe use of the repaired skin. The gap between the outer side surface of the filling block and the outer surface of the first skin is used to fill the adhesive.

[0014] Furthermore, the filling block and the repair skin are bonded together with an adhesive, and there is no adhesive between the repair skin and the first skin. The adhesive makes the repair skin bonded to the filling block, and when the adhesive is not filled between the repair skin and the first skin, the protruding height of the repair skin relative to the first skin can be reduced, and a high protruding part is not formed on the box sandwich panel, which affects the normal use of the box sandwich panel, especially when equipment needs to be installed in the repair area of ​​the box sandwich panel.

[0015] To ensure the connection strength of the repaired skin, the overlap width between the repaired skin and the first skin is 5-10 mm.

[0016] Furthermore, in the repair hole, a buried iron is installed on the side of the filling block facing the second skin. After the buried iron is installed, other equipment can be added to the repair area.

[0017] Secondly, the present application also provides a construction method for a repair structure of a box sandwich panel, which is used to realize the repair structure in the above technical solutions, and the construction method specifically includes the following steps:

[0018] (1) Cutting holes: A rectangular cut is made at the part of the sandwich panel that needs to be repaired. The cut first skin is peeled off, and the corresponding core material is cut off to form a rectangular repair hole. A filling block with adhesive applied on the outer surface is inserted into the repair hole, and the filling block is against the bottom surface of the repair hole. The part that needs to be repaired is a damaged part or a part that needs additional buried iron. Of course, it can also be a part that happens to be damaged.

[0019] After the repair hole is opened, the edge of the opening of the first skin needs to be polished to remove burrs, and the welding part of the first skin needs to be surface treated, specifically, the paint and coating of the welding part need to be polished clean;

[0020] (2) Apply adhesive on the bonding surface of the repaired skin, and then cover the repair hole with the bonding surface of the repaired skin; when applying the adhesive, the adhesive should be 10-30 mm away from the edge of the repaired skin; that is, the adhesive should not be applied in the area 10-30 mm away from the edge of the repaired skin; and the applied adhesive should not penetrate into the gap between the repaired skin and the first skin after being squeezed;

[0021] The edges of the repaired skin should also be polished smooth, and the bonding surface and the area opposite to the repair hole should be polished rough and clean to facilitate bonding; the welding area of ​​the repaired skin should also be surface treated, and the paint and coating of the welding area should be polished clean;

[0022] (3) Clamp the repair skin onto the sandwich panel of the car body with a tool, and then weld the repair skin onto the first skin by laser welding;

[0023] The first skin is an aluminum plate, a carbon steel plate or a stainless steel plate. When the first skin is an aluminum plate, the thickness of the first skin is 0.8-1.2 mm, and the welding power is 1.27-1.43 kw; when the first skin is a carbon steel plate or a stainless steel plate, the thickness of the first skin is 0.6-2 mm, and the welding power is 0.90-1.05 kw;

[0024] Laser welding parameters:

[0025] Swing displacement: controlled at 1.5-2.0mm;

[0026] Type of shielding gas: industrial argon gas, purity ≥ 99.999%;

[0027] Welding moving speed: 1.0-1.2m / min;

[0028] Welding operations: including positioning and welding, as follows:

[0029] Positioning: First use intermittent welding to locate the position of the repaired skin, the weld length is controlled at 6-20mm, and the spacing is 60-100mm;

[0030] Welding: Tilt the welding gun head 40-50 degrees and move the welding gun along the gap to fuse the repair skin and the first skin together;

[0031] (4) Curing: After welding, the adhesive is cured to a thickness of 0.2-0.3 mm;

[0032] During curing, the adhesive is cured by using room temperature curing, radiation heating curing or heat transfer heating;

[0033] When curing at room temperature, the curing time is 5-24h;

[0034] When radiation heating is used for curing, the curing time is 3-5h;

[0035] When heat transfer heating is used for curing, the curing time is 1-2 hours.

[0036] When using radiation heating for curing, a drying lamp or a heater called a small sun can be used. When using heat transfer heating for curing, a heating sheet such as a silicone rubber electric heating sheet can be used. The existing electric heating sheets can meet the needs of this application and will not be described in detail. The above methods can be selected according to the size of the composite sandwich panel and the required construction progress. For repair areas below 200mm×200mm, heat transfer heating curing is suitable.

[0037] When this construction method is used to complete the repair structure, due to the use of laser welding technology, the repair skin is directly welded to the first skin around the repair hole, and metal strips and corresponding rivets are no longer required. During construction, the construction efficiency can be effectively improved and construction time can be saved.

[0038] Compared with argon arc welding and carbon dioxide gas shielded welding, laser welding releases less heat, has small metal deformation at the weld, has high welding strength, and the skin surface is beautiful after repair without cracking.

[0039] This construction method can be used for welding the first skin of the sandwich panel of the compartment plate, which is made of metal material. The first skin can be specifically made of aluminum plate, carbon steel plate or stainless steel plate. Since the first skin and the repair skin are melted and bonded together during laser welding, the sealing between the repair skin and the first skin is ensured, and good waterproof performance is achieved.

[0040] Furthermore, in order to ensure the bonding strength while avoiding the influence of too thick adhesive on the construction efficiency, in step (2), when applying the adhesive on the bonding surface of the repaired skin, the amount of the adhesive applied is 0.3-0.8 kg / m 3 With the above-mentioned amount of adhesive applied, the connection strength between the repaired skin and the first skin can be ensured, and uncontrolled flow of the adhesive can be avoided. In addition, too thick an adhesive will also delay the solidification time, which is not conducive to improving construction efficiency.

[0041] Further, in step (2), when the viscosity of the adhesive is 2000-3500mPa.s and 40°C, after the application is completed, the adhesive is cured and the repaired skin is pasted to the body sandwich panel 15-30min before gelation. The adhesive with the above viscosity is a conventional adhesive with good construction performance. In order to ensure the bonding effect, the repaired skin needs to be pasted to the body sandwich panel 15-30min before gelation. In addition, since the adhesive is a liquid with strong fluidity, and when the body sandwich panel is in a vertical state, the adhesive is more likely to flow downward. In order to prevent the adhesive from entering between the repaired skin and the first skin, additional protection work needs to be increased to prevent the adhesive from entering between the repaired skin and the first skin. After the adhesive is applied, the adhesive is cured, which can increase the viscosity of the adhesive and reduce its fluidity, so that there is no adhesive between the repaired skin and the first skin, thereby ensuring the welding quality between the repaired skin and the first skin. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of an embodiment of a repair structure of a compartment sandwich panel.

[0043] Figure 2 This is a schematic diagram after the repair hole is opened on the sandwich panel of the car body.

[0044] Figure 3 This is a schematic diagram after installing buried iron in the repair hole.

[0045] Figure 4 It is a schematic diagram after the filling block is filled in the repair hole and the bonding of the repair skin is completed.

[0046] Figure 5 This is a schematic diagram of welding the repair skin and the first skin.

[0047] Figure 6This is a schematic diagram of curing. DETAILED DESCRIPTION

[0048] The repair structure of the car body sandwich panel will first be described below.

[0049] Figure 1 In the figure, arrows M marked at appropriate positions indicate the thickness direction of the sandwich panel 10 of the car body.

[0050] See also Figure 1 The compartment sandwich panel 10 includes a core material 11 and a first skin 12 and a second skin 13 respectively laid on both sides of the core material 11 in the thickness direction, and the first skin 12 is a metal skin. Specifically in this embodiment, the first skin is made of a 1.2 mm thick aluminum plate. A frame 15 is embedded in the core material 11.

[0051] The repair structure includes a repair hole 19 opened on the car body sandwich panel 10, and the repair hole 19 is formed by cutting the first skin toward the core material along the thickness direction of the car body sandwich panel, that is, the repair hole 19 includes a hole opened on the first skin and a hole opened on the core material 11, and the repair hole 19 does not penetrate the second skin 13.

[0052] The repair hole 19 is filled with a filling block 22, and a repair skin 21 covers the repair hole 19. The repair skin 21 is made of the same material as the first skin, and is also made of an aluminum plate, and is welded to the first skin 12. It can be understood that in other embodiments, when the first skin is made of a carbon steel plate or a stainless steel plate, the repair skin is also made of the same material, that is, a carbon steel plate or a stainless steel plate.

[0053] In this embodiment, the thickness of the repaired skin is 0.8 mm. It is understood that in other embodiments, the thickness of the repaired skin may also be 0.6 or 0.7 mm. The filling block 22 is cut from the same material as the core material 11.

[0054] The outer circumference of the filling block 22 is in contact with the inner circumference of the repair hole 19 and they are bonded together with adhesive. The filling block 22 has an outer side surface 221 facing away from the second skin 13, and the outer side surface 221 is 0.2 mm lower than the outer surface 121 of the first skin 12, so that an adhesive accommodating cavity is formed between the outer side surface 221 of the filling block 22 and the repair skin, so as to reduce the additional outward pressure on the repair skin caused by the filling block due to the supporting effect of the adhesive.

[0055] The filling block and the repair skin are bonded together with adhesive, and there is no adhesive between the repair skin and the first skin. In this embodiment, the overlap width L between the repair skin and the first skin is 7 mm.

[0056] Since the repaired part in this embodiment faces the frame 15 and needs to be supplemented with embedded iron, in this embodiment, an embedded iron 23 is installed on the side of the filling block 22 facing the second skin 13 and the embedded iron is supported on the frame 15 .

[0057] It can be understood that in other embodiments, when there is no need to add buried iron, the buried iron can be eliminated and the filling block can be directly placed against the bottom surface of the repair hole.

[0058] Of course, repair holes can also be opened in areas without frames but with damage.

[0059] The construction method of the above-mentioned repair structure is described below.

[0060] The construction method comprises the following steps:

[0061] (1) Cut into holes, see Figure 2 , cut the compartment sandwich panel 10 in a rectangular shape at the part to be repaired, peel off the cut first skin, cut off the corresponding core material, expose the frame 15, and clean the exposed surface of the frame to form a rectangular repair hole 19. Figure 3 Then, the embedded iron 23 coated with adhesive is placed in the repair hole 19, and the embedded iron is bonded to the frame 15. According to different requirements, the embedded iron can be fixed to the frame with screws or rivets.

[0062] See also Figure 4 , a filling block 22 with adhesive applied on the outer surface is inserted into the repair hole 19, and the filling block abuts against the buried iron 23. It can be understood that in other embodiments, when the buried iron is not required, the filling block directly abuts against the bottom surface of the repair hole.

[0063] (2) Please continue reading Figure 4 , apply adhesive on the bonding surface of the repair skin 21, and then cover the bonding surface of the repair skin on the repair hole; when applying the adhesive, the amount of adhesive applied is 0.6kg / m 3 , the adhesive is 15mm away from the edge of the repair skin; to avoid the adhesive flowing between the repair skin and the first skin when the repair skin is pressed.

[0064] In this embodiment, the viscosity of the adhesive is 3000 mPa.s, and the temperature is 40°C. After being applied, the adhesive is cured, and the repaired skin is pasted to the sandwich panel of the car body 20 minutes before gelling.

[0065] (3) Please refer to Figure 5The repair skin is clamped on the body sandwich panel with a tool 50, and then the repair skin is welded to the first skin with a laser welder. In this embodiment, the tool 50 includes a clamping plate 51, which is pressed against the repair skin and pressed against the body sandwich panel through the repair skin.

[0066] Since in this embodiment, the first skin and the repair skin are both made of aluminum plates, the welding power is 1.35kw. In other embodiments, when the first skin and the repair skin are both made of aluminum plates, the welding power can also be 1.27, 1.39 or 1.43kw.

[0067] It can be understood that in other embodiments, when the first skin and the repair skin are both made of carbon steel plates or stainless steel plates, the welding power is 0.90, 0.95, 1.00 or 1.05 kw.

[0068] In the present application, the first skin is an aluminum plate, a carbon steel plate or a stainless steel plate. When the first skin is an aluminum plate, the thickness of the first skin is 0.8-1.2 mm, and the welding power is 1.27-1.43 kw; when the first skin is a carbon steel plate or a stainless steel plate, the thickness of the first skin is 0.6-2 mm, and the welding power is 0.90-1.05 kw;

[0069] Laser welding parameters:

[0070] The swing displacement of the laser welder is controlled at 1.7mm.

[0071] Type of shielding gas: industrial argon gas, purity ≥ 99.999%;

[0072] Welding moving speed: 1.1m / min;

[0073] Welding operations: including positioning and welding, as follows:

[0074] Positioning: First use intermittent welding to locate the position of the repaired skin, the weld length is controlled at 12mm and the spacing is 80mm;

[0075] Welding: Tilt the welding gun head 30 at 45 degrees and move the welding gun along the gap to fuse the repair skin and the first skin together.

[0076] (4) Curing, please refer to Figure 6 In this embodiment, heat transfer heating curing is adopted, and the curing time is 1.5 hours. During curing, the silicone rubber heating sheet 40 is attached to the side of the compartment sandwich panel with the repaired skin and covers the repaired skin, and then the compartment sandwich panel is heated at 50-65°C to cure the adhesive, and the cured thickness of the adhesive is 0.2mm. Figure 6 In the figure, reference numeral 41 denotes a power line of the silicone rubber heating sheet 40 .

[0077] It is understood that in other embodiments, the adhesive may be cured by room temperature curing or radiation heating curing. When room temperature curing is adopted, the curing time is 5-24 hours. When radiation heating curing is adopted, the curing time is 3-5 hours. When performing radiation heating curing, a drying lamp or a heater called a small sun may be used.

Claims

1. A repair structure for a sandwich panel of a compartment, characterized in that: The compartment sandwich panel comprises a core material and a first skin and a second skin respectively laid on both sides of the core material in a thickness direction, and the first skin is a metal skin, the repair structure comprises a repair hole opened on the compartment sandwich panel, the repair hole is formed by cutting the first skin toward the core material along the thickness direction of the compartment sandwich panel, the repair hole does not penetrate the second skin, a filling block is filled in the repair hole, a repair skin covers the repair hole, the repair skin covers the repair hole, the material of the repair skin is the same as that of the first skin, and the repair skin is welded to the first skin; The filler piece is cut from the same material as the core.

2. The repair structure according to claim 1, characterized in that: The outer circumference of the filling block is in contact with the inner circumference of the repair hole and they are bonded together by an adhesive.

3. The repair structure according to claim 1, characterized in that: The filling block has an outer side surface facing away from the second skin, and the outer side surface is 0.2-0.3 mm lower than the outer surface of the first skin.

4. The repair structure according to claim 1, characterized in that: The filling block and the repair skin are bonded together by adhesive, and there is no adhesive between the repair skin and the first skin.

5. The repair structure according to claim 1, characterized in that: The thickness of the repaired skin is 0.6-0.8mm.

6. The repair structure according to claim 1, characterized in that: The overlap width between the repair skin and the first skin is 5-10mm.

7. The repair structure according to claim 1, characterized in that: In the repair hole, buried iron is installed on the side of the filling block facing the second skin.

8. The construction method of the repair structure of the box sandwich panel according to any one of claims 1 to 7, characterized in that: The steps include: (1) Cutting holes: Cut the sandwich panel of the car body in a rectangular shape at the location to be repaired, peel off the cut first skin, and cut off the corresponding core material to form a rectangular repair hole. Insert a filling block with adhesive on the outer surface into the repair hole, and place the filling block against the bottom surface of the repair hole; (2) Apply adhesive to the bonding surface of the repaired skin, and then cover the bonding surface of the repaired skin over the repair hole; when applying the adhesive, the adhesive should be 10-30 mm away from the edge of the repaired skin; (3) Clamp the repair skin onto the sandwich panel of the car body with a tool, and then weld the repair skin onto the first skin by laser welding; The first skin is an aluminum plate, a carbon steel plate or a stainless steel plate. When the first skin is an aluminum plate, the thickness of the first skin is 0.8-1.2 mm, and the welding power is 1.27-1.43 kw; when the first skin is a carbon steel plate or a stainless steel plate, the thickness of the first skin is 0.6 mm-2 mm, and the welding power is 0.90-1.05 kw; Laser welding parameters: Swing displacement: controlled at 1.5-2.0mm; Type of shielding gas: industrial argon gas, purity ≥ 99.999%; Welding moving speed: 1.0-1.2m / min; Welding operations: including positioning and welding, as follows: Positioning: First use intermittent welding to locate the position of the repaired skin, the weld length is controlled at 6-20mm, and the spacing is 60-100mm; Welding: Tilt the welding gun head 40-50 degrees and move the welding gun along the gap to fuse the repair skin and the first skin together; (4) Curing: After welding, the adhesive is cured to a thickness of 0.2-0.3 mm; During curing, the adhesive is cured by using room temperature curing, radiation heating curing or heat transfer heating; When curing at room temperature, the curing time is 5-24h; When radiation heating is used for curing, the curing time is 3-5h; When heat transfer heating is used for curing, the curing time is 1-2 hours.

9. The construction method according to claim 8, characterized in that: In step (2), when applying adhesive to the bonding surface of the repaired skin, the amount of adhesive applied is 0.3-0.8 kg / m 3 .

10. The construction method according to claim 8, characterized in that: In step (2), when the viscosity of the adhesive is 2000-3500 mPa.s at 40°C, it is cured after being applied, and the repaired skin is pasted to the sandwich panel of the car body 15-30 minutes before gelation.

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